Pharmacology: Anxiolytic, Sedative and Hypnotic Drugs

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Questions and Answers

What is the effect of benzodiazepines on the GABAA receptor?

They directly open the Cl- channel

They increase the opening time of the Cl- channel

They increase the affinity of GABAA receptors to GABA (correct)

They decrease the gravimetric potency of GABA

What is the mechanism of action of barbiturates on the GABAA receptor?

They decrease the flow of chloride by decreasing the time the channel is open

They increase the binding of GABA to its own receptor

They directly open the Cl- channel and increase the flow of chloride (correct)

They inhibit the binding of GABA to its own receptor

What is the effect of benzodiazepines on the serotonergic system?

They increase the serotonergic tone

They decrease the serotonergic tone

They have no effect on the serotonergic system

They interact with the serotonergic system to produce anxiolytic effects (correct)

What is the characteristic of benzodiazepines that makes them more desirable than barbiturates?

They have a wider therapeutic index Signup and view all the answers

Why are oxazepam and lorazepam preferred in the elderly and in liver dysfunctions?

They do not require conversion to active metabolites Signup and view all the answers

What is the primary difference between an anxiolytic effect and a sedative effect?

Anxiolytic effect normalizes attention, while sedative effect reduces vigilance Signup and view all the answers

Which of the following drugs is a non-benzodiazepine BZ receptor agonist?

Buspirone Signup and view all the answers

What is the primary mechanism of action of benzodiazepines?

Activation of the GABAA receptor, leading to hyperpolarization Signup and view all the answers

What is the primary effect of hypnotic drugs at high doses?

General anesthesia and coma Signup and view all the answers

What is a characteristic of benzodiazepines in terms of their effect on muscle tone?

They reduce striated muscle tone at sedative doses Signup and view all the answers

Which of the following is NOT a mechanism of action of hypnotic drugs?

Analgesic effect Signup and view all the answers

What is a use of diazepam as an anxiolytic?

To calm patients during endoscopic examinations Signup and view all the answers

What is a side effect of benzodiazepines when used hypnotically?

Rebound insomnia Signup and view all the answers

What is a characteristic of benzodiazepines in terms of their effects on memory?

They impair anterograde memory in a dose-dependent manner Signup and view all the answers

What is a precaution to be taken when using benzodiazepines?

They should not be used in combination with alcohol Signup and view all the answers

What is the age limit for the use of diazepam in children?

Less than 2 years Signup and view all the answers

What is the mechanism of action of flumazenil in benzodiazepine intoxication?

Competitive antagonist Signup and view all the answers

What is the characteristic of azapiron buspirone?

It has an anxiolytic effect with no tolerance and dependency Signup and view all the answers

What is the duration of action of long-acting barbiturates?

6 hours or more Signup and view all the answers

What is the effect of barbiturates on spontaneous motor activity?

Decrease in spontaneous motor activity Signup and view all the answers

Which of the following is NOT a treatment option for post-traumatic stress disorder?

Anticholinergics Signup and view all the answers

What is the prevalence rate of insomnia in the population?

30-40% Signup and view all the answers

Which of the following is a sleep hygiene technique for insomnia?

Removing daytime sleeps Signup and view all the answers

What is the goal of a good sleep pill?

Reduce the REM pattern and duration of REM Signup and view all the answers

Which of the following is a cause of insomnia due to medical conditions?

Asthma Signup and view all the answers

What is the effect of barbiturates on respiratory rate when given in a hypnotic dose?

Slightly decreases respiratory rate Signup and view all the answers

What is the effect of barbiturates on the vasomotor center and myocardium?

Depresses the vasomotor center and myocardium Signup and view all the answers

What is the use of phenobarbital in the treatment of neonates?

Treatment of hyperbilirubinemia and kernicterus Signup and view all the answers

What is the interaction between barbiturates and alcohol?

Alcohol potentiates the effects of barbiturates Signup and view all the answers

What is the effect of barbiturates on bowel motility?

Decreases bowel motility Signup and view all the answers

What is the primary effect of hypnotic drugs on total sleep time?

It does not change the ratio of total sleep time Signup and view all the answers

Which of the following hypnotics is suitable for patients who have difficulty maintaining sleep?

Medium-duration hypnotics Signup and view all the answers

What is the maximum duration of use of barbiturates and other types of hypnotics?

2 weeks Signup and view all the answers

Which of the following drugs does not shorten REM time significantly?

Benzodiazepine derivatives Signup and view all the answers

What is the effect of benzodiazepine receptor agonists on sleep?

They shorten the time to sleep and prolong total sleep time Signup and view all the answers

What is the characteristic of non-benzodiazepine agonists?

They bind to the same place where benzodiazepines bind at GABA A receptors Signup and view all the answers

What is the effect of trazodone on sleep?

It increases deep sleep Signup and view all the answers

What is the effect of melatonin on the body?

It regulates the sleep-wake (circadian rhythm) cycle Signup and view all the answers

What is the effect of valerian on sleep?

It makes it easier to fall asleep Signup and view all the answers

What is the characteristic of non-benzodiazepine agonists in terms of their side effects?

They have less frequent psychomotor, memory problems, and rebound phenomenon Signup and view all the answers

Study Notes

Anxiolytic, Sedative, and Hypnotic Effects

Anxiolytic effect: reducing psychomotor reactivity exceeding normal limits to a normal level of attention and responsiveness
Sedative effect: reducing vigilance and psychomotor reaction ability below normal limits
Hypnotic effect: inducing sleep

Hypnos Sedative Medications

Benzodiazepines
Non-benzodiazepine BZ receptor agonists
Barbiturates
Azopyrones (e.g., buspirone, gepiron, ipsapiron) - anxiolytic
Antihistamines (e.g., hydroxyzine, doxylamine, diphenhydramine, metaprine, promethazine)
Melatonin, ramelteon
Others (e.g., aldehydes, propanediol, carbamate derivatives, piperidindiones, quinazolins)

Effects of Hypnos Sedatives

Dose-dependent and generalized CNS depression
Drowsiness below sedative dose
Sedative (anxiolytic) at small doses
Hypnotic at high doses (narcotic)
General anesthesia and coma at overdose
Anticonvulsant and central muscle relaxant effects

Mechanisms of Action of Hypnos Sedatives

BZ receptors: BZ1 (anxiolytic and sedative), BZ2 (muscle relaxation, CNS depression, and psychomotor changes), BZ3 (located in the SSS and periphery, responsible for tolerance and withdrawal symptoms)
GABA: agonist (mucimol), antagonist (bicuculin)
Benzodiazepines: reverse agonists and antagonists (allosteric) on the junction of alpha and gamma subunits of the GABAA receptor
Barbiturates: allosteric, picrotoxin (blocks the channel directly)
Ethanol, ivermectin, etomidate, propofol, and gas general anesthetics

Benzodiazepines

Mechanism of action: activating the binding points (BZ1 and BZ2 receptors) on the GABAA receptor, causing the opening of chloride channels, hyperpolarization, and postsynaptic or presynaptic inhibition
Interactions with other mediators: affecting the serotonergic system, reducing serotonergic tone, inhibiting the locus coeruleus, suppressing the central cholinergic system, and inhibiting adenosine uptake
Classification:
- Long-acting (e.g., diazepam, klonazepam, klorazepat, medazepam, flurazepam, kuazepam)
- Medium-acting (e.g., oxazepam, alprazolam, lorazepam, temazepam, nitrazepam, flunitrazepam)
- Short-acting (e.g., midazolam, triazolam)

Properties of Benzodiazepines

Lipophilic
Quickly absorbed from the GI canal
Elimination half-life varies from person to person, influenced by age
Preference for oxazepam and lorazepam in the elderly and liver dysfunctions
Metabolized by CYP 3A4 and CYP2C19, excreted in the form of conjugates
Long-acting benzodiazepines: no long effects when used in a single dose, requiring 5-14 days of treatment for a significant effect
Short- and medium-acting benzodiazepines: greater potential for physical addiction and risk of amnesia

Uses of Benzodiazepines

Anxiety disorders (e.g., panic reactions, phobias)
Sleep disorders
Induction of general anesthesia and short-term surgical or diagnostic interventions
Anticonvulsants (e.g., clonazepam, midazolam, nitrazepam, triazolam)
Striated muscle rigidity and spasm, nocturnal myoclonus, athatosis
Tetanus, febrile convulsion, status epilepticus, and withdrawal syndrome

Side Effects of Benzodiazepines

Drowsiness, mental and psychomotor dysfunction
Impaired motor coordination, ataxia, nystagmus, drunken speech
Anterograde amnesia, dementia
Disruption in jobs that require skill
Headache, dizziness, nausea, vomiting
Decreased visual acuity, joint pain
Addiction: physical dependence occurs without significant psychic dependence in use for more than 6 weeks

Azapirones

Partial agonist at serotonergic receptors of type 5HT1A
Reduces serotonergic activity in the limbic system
No hypnotic effect, no tolerance, and non-addictive
Superiority over benzodiazepines: fewer psychomotor disorders, less sedation and amnesia, no interaction with alcohol, and no tolerance and dependence with benzodiazepines and other sedatives

Barbiturates

Classification by duration of action:
- Long-acting (e.g., phenobarbital, sedative and anticonvulsive)
- Medium-acting (e.g., pentobarbital, allobarbital, amobarbital, hypnotic, butalbital, siklobarbital)
- Short-acting (e.g., sekobarbital, hexobarbital)
- Very short-acting (e.g., thiopental, IV anesthetic)
Pharmacokinetic properties: quickly absorbed through the GI duct, absorbed and used through the rectum, IM absorption is quick, easily passes into milk
Pharmacodynamic properties: sedative and hypnotic effect, anticonvulsant effect, general anesthesia

Side Effects of Barbiturates

Drowsiness and residual effect
Impaired cognitive functions in infants and children
Dependence and tolerance
Rebound insomnia
Allergic reactions, respiratory depression, paradoxical excitation
Exacerbation of porphyria, local pain, and myalgia

Drug Interactions

Additive interaction with other anxiolytic and hypnotic drugs
Alcohol potentiates the effects of barbiturates
Induction of microsomal enzymes (CYP3A4, CYP2C9) and reduced plasma levels of drugs metabolized by these enzymes

Acute Barbiturate Poisoning

Symptoms: excessive drowsiness, confusion, slurred speech, decreased respiratory rate, sometimes rapid and superficial breathing
Treatment: respiratory support, prevention and treatment of shock, maintenance of renal function, forced diuresis, peritoneal dialysis, hemodialysis

Other Hypnosedative Drugs

Dexmedetomidine: central sympatholytic, sedative, and analgesic effects
Agomelatine: MT1 and 2 and 5-HT2C receptors

Anxiety Disorders

Generalized anxiety disorder
Panic disorder
Social anxiety disorder
Post-traumatic stress disorder
Obsessive-Compulsive disorder

Basic Sleep Disorders

Insomnia
Sleep breathing disorders (e.g., obstructive sleep apnea syndrome)
Excessive sleepiness that is not due to breathing disorder during sleep (e.g., narcolepsy, hypersomnia)
Circadian rhythm disturbances
Parasomnias (e.g., making the patient's environment safe, MAO inh, alcohol and caffeine restriction)
Sleep-related movement disorders (e.g., restless legs syndrome)### Sleep-Related Movement Disorders
Elimination of iron deficiency, dopamine agonists, benzodiazepine, carbamezapine, and gabapentin can be used to treat sleep-related movement disorders

Insomnia

Insomnia is characterized by difficulty falling asleep, difficulty maintaining sleep, frequent awakenings, and early awakening
Its prevalence in the population is between 30-40%, and it accounts for 50-80% of all sleep disorders

Sleep Hygiene

Getting up at the same time every morning
Ensuring consistent bedtime and removing daytime sleeps
Exercising regularly, but avoiding physically strenuous activities until 3-4 hours before bedtime
Creating a sleep-conducive environment with minimal noise, light, and heat
Avoiding eating close to bedtime (up to 2 hours before bedtime)
Avoiding caffeine, alcohol, cola drinks, and tobacco use at least 6 hours before bedtime
Not forcing oneself to sleep in bed when unable to sleep at night
Using relaxation techniques such as breathing exercises before bed

Sleep Periods

A good sleep pill should reduce the REM pattern and duration of REM without changing the total sleep time
Hypnotic drugs shorten the time it takes to fall asleep and some shorten REM time significantly
Short-acting hypnotics are suitable for those who have difficulty falling asleep
Medium-duration hypnotics are suitable for those who have difficulty starting and maintaining sleep
Hypnotics with a long duration of action are suitable for those who wake up early in the morning and have anxiety during the day

Pharmacological Treatment of Insomnia

Benzodiazepine Receptor Agonists (estazolam, flurazepam, quazepam, temazepam, triazolam) shorten the time to sleep, prolong total sleep time, reduce wakefulness, and prolong NREM
Non-benzodiazepine agonists (Zopiclone, Eszopiclone, Zolpidem, Zaleplon, Indiplon) bind to GABA A receptors and have weaker muscle relaxant and anticonvulsant effects
Antidepressants (trazodone, mirtazapine, amitriptyline) increase deep sleep and do not shorten REM
Antihistamines (diphenhydramine, hydroxyzine, doxylamine) can be used to treat insomnia
Melatonin and ramelteon (MT1 and 2 receptor agonist) regulate the sleep-wake cycle and can treat jet lag
Valerian (Valeriana officinalis) makes it easier to fall asleep and regulates GABAa receptors

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Description

Learn about anxiolytic, sedative and hypnotic effects of drugs, including their definitions and effects on psychomotor reactivity and vigilance.